The rise of Christianity from the death of Jesus to the establishment of the first Christian church is often portrayed as a rapid, almost seamless, movement in history. Sociologist Stark (Theory of Religion) here ponders why Christianity succeeded as it did in the early years of the first century. Stark uses contemporary social-scientific data, about why people join new religious movements and how religions recruit members, to investigate the formative history of Christianity. Among his findings is that the key factors in Christianity's success included the desire on the part of its members to assimilate into the dominant culture, the conversion of pagan men through intermarriage with Christian women and the commitment to voluntary martyrdom. Stark's conclusion that the rapid rise of early Christianity was due mainly to high fertility rates and social policies rather than to faith in the messianic message of Jesus is likely to generate spirited argument. (July)